To successfully manage the state road network, MnDOT needs a thorough understanding of the number and type of vehicles on the road. To obtain this information, the agency upgraded existing inductive loop infrastructure at select locations to enable these sensors to collect vehicle classification data. This project evaluated the accuracy of the inductive loop upgrade and its life cycle costs to determine its viability for future use on Minnesota roads.
Continue reading An Evaluation of Vehicle Identification Technology
Refining Max-Pressure Traffic Signal Control to Improve Traffic Flow
Effective traffic signal control technologies facilitate optimal traffic flow and travel time. Building on previous research, this project made significant progress toward field implementation of a novel adaptive signal control technology. This research phase demonstrated the max-pressure traffic signal algorithm can successfully integrate into Hennepin County traffic signal hardware and respond to changing traffic conditions in real time, providing confidence to move to the next step and test the system in the field.
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Adding fibers to concrete may help create long-lasting roads
Originally published in CTS News, March 19, 2025
Thin pavements—in which new pavements are constructed over an existing base layer—can be an economical option for low- and moderate-volume roads. However, thinner concrete roads are prone to distress caused by weather and traffic loads. The solution, U of M researchers found, may be to add small synthetic fibers to the concrete.
Continue reading Adding fibers to concrete may help create long-lasting roads
Developing Technology to Prevent Vehicles from Running Red Lights
Crashes that result from vehicles driving through red lights are often very serious because they are typically right-angle or side-impact crashes. While newer vehicles have many standard safety features such as lane departure warning and brake assistance systems to support drivers, they do not have technologies to help prevent driving through red lights. This project developed an algorithm that integrated traffic light phasing information with GPS data to warn drivers when they were approaching a red light, providing valuable driver assistance and improving traffic safety and efficiency.
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Comparing the Effectiveness of No Right Turn on Red Sign Types at Traffic Signals
Preventing right turns on red at traffic signals is a generally effective pedestrian safety measure. But when pedestrians are absent, allowing right turns on red can improve traffic flow. Unlike static signs that prohibit right turns on red, dynamic No Right Turn on Red (NRTOR) signs can be activated when pedestrians are present. Comparing driver compliance with dynamic and static signs indicated that each sign type may have its own benefits.
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Assessing Reliability and Resilience on Freeway Corridors
Drivers and businesses benefit from a freeway network that is predictable and able to withstand disturbances such as construction, incidents and poor weather. To provide a high level of service on freeways, traffic managers monitor and assess traffic flows and speeds under various conditions. In this project, investigators analyzed and identified the most vulnerable portions of the Twin Cities freeway network and enhanced an analysis tool to provide better estimates of travel-time reliability and operational resilience.
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Repairing In-Water Bridge Supports Using Innovative Methods and Materials
In recent years, advancements in bridge repair techniques and technologies promise to offer more options for strengthening an existing bridge’s in-water piles, eliminating the need to reroute both water and traffic. This project investigated other states’ experiences with several products on the market and provided an opportunity for Minnesota’s engineers to evaluate two vendors’ systems on a bridge in need of restoration.
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Examining Driver Preferences for Lane Line Patterns and Widths
Pavement markings that clearly delineate lanes are important for reducing crashes and improving the safety of drivers. The configurations of these pavement markings—primarily the width and length of the line and the spacing of broken lines—vary from state to state. This project identified driver preferences for pavement marking patterns and widths, which can increase visibility and improve safety.
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Examining off-peak transit behaviors to improve transit equity
Originally published in Catalyst, February 19, 2025
Transit service planning has traditionally focused on peak trips and the needs of “rush hour” commuters rather than off-peak travel. Often, off-peak trips are taken by shift-based essential workers and those who cannot or do not drive. The COVID-19 pandemic further underscored the need for a closer examination of these trips to improve social equity.
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Understanding the Performance of Road Base Stabilization Additives
Full-depth reclamation (FDR)—an effective and efficient pavement reconstruction method—can be made even more sustainable by strengthening the road base. Laboratory and field testing of proprietary stabilizers used to amend FDR material illustrated improvements in pavement stiffness and economic benefits over time. New pavement design standards for base stabilizers can guide road engineers in choosing the optimal products for sustainable roads.
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Crossroads 